Modern infrastructural design and architecture are evolving due to rapid improvements in modern technology and material science. This has raised the bar, calling for construction and engineering companies to rise to the occasion with improvements in foundation systems.
Obstructions can be difficult, because you often do not know they are there until you begin to install a deep foundation. Helical piles cannot install through obstructions; however, here we highlight the different options you have for dealing with obstructions while installing helical piles. One of the benefits of helical piles is that you do not have to abandon the pile. In most cases, it can be removed and reinstalled (unlike other deep foundation options).
Helical piles are an excellent foundation solution for the oil and gas industry, both in congested and remote areas. They are easy to install and can be uninstalled (if necessary) and reused at another location. They are displacement piles, so they produce no spoils, no time is lost waiting for concrete to cure before loading, and they are installed with minimal environmental impact. For oil and gas applications, helical piles can be the most suitable foundation solution in the segment.
Imagine trying to conduct “business as usual” in a building that is being renovated with a new interior second floor addition. That’s exactly what happened on this project.
Have you ever needed to estimate the axial capacity of a helical pile? You could calculate helix bearing and shaft friction by hand, but there is a better method. Use HeliCAP® v3.0 Helical Capacity Design Software! HeliCAP is software that estimates the axial capacity of helical piles, is free to use, and accessible from any computer, smartphone, or tablet with an internet connection and a web browser. A desktop or laptop computer with the Google Chrome web browser is recommended for best results.
The shaft type/size of a helical pile is critical to both the axial and lateral capacity – especially for compression in soft/loose overburden soils where lateral stability of the shaft must be considered. The following is a brief summary of the 4 different shaft types commonly used for helical piles and their relative advantages and disadvantages based on site conditions and application. It is very important to understand that helical pile installation must be considered in the design process.
There are several solutions engineers and contractors can choose from when a deep foundation is required. With a deep foundation the structure’s load is transmitted to soils that are deeper in the ground. A deep foundation is used when a shallow foundation is not possible, not practical, or will not carry the load. Examples are weak, unstable, or expansive surface soils. Two popular options for deep foundations are helical piles and drilled shafts, also known as drilled piers or caissons.
The first question we often get is, “are helical piles a new technology?”. Though they are growing each year in use and popularity, many Geotechnical and Structural Engineers are often unfamiliar with the technology. Complicating the matter is that, in many cases, students who will be our future engineers know very little about helical piles and their history. The truth is that helical piles [a.k.a. screws, screw piles, helical piers, helicals] appeared on the scene in the early 1800s. Alexander Mitchell (1780-1868) applied the use of screw piles in 1836 for moorings and, in 1838, for a lighthouse foundation. To put things into perspective, screw piles preceded the advent of Portland Cement [1850’s] and first use of a gasoline-powered automobile . According to some historians, screw piles were the major foundation technology of the 19th century.
Any contractor can tell you that a structure is only strong as its foundation. Deep foundations transmit the structure’s load to soils that are deeper in the ground. A deep foundation is used when a shallow foundation is not possible, not practical, or will not carry the load, such as in weak, unstable, or expansive surface soils. Proper site preparation and installation is key to the success of any job – starting with the foundation.
Deep foundation pricing is multifaceted and a one price fits all approach can lead to unexpected costs. To break down the pricing, the following list can help provide a better understanding of the top 4 factors that can affect pile prices and why they are important pieces of information when looking for estimates: